Electric bell.



F. S. TUCKER.

ELECTRIC BELL. nrmonxon 1mm 11121.19;

Patented Jan. 5,1915.

nu ulmum mn a 1.0 mmm u I ma WASHINhI-IN UNITED STATES PATENT FRANK S. TUCKER, F BOSTON, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO EDYVIN P. SEVERANCE, OF BBOCKTON, MASSACHUSETTS.

ELECTRIC BELL.

Specification of Letters Patent.

Patented Jan. 19 15.

Application filed February 6, 1914. Serial No. 818,914.

To all whom. it may concern:

Be it known that I, FRANK S. TUCKER, a citizen of the United States, residing at .Roxbury, Boston, in the county of Suil'olk and State of Massachusetts, have invented certain new and useful Improvements in Electric Bells; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to electric bells, and particularly to the striker mechanism.

The object of the invention is to simplify the construction and cheapen the cost of manufacture.

With this object in view, the present invention consists in the electric bell hereinafter described and particularly pointed out in the claims.

in the drawings which illustrate the preferred embodiment of the invention, Figure l is a front elevation, Fig. 2 is a side elevation taken partlv in section along the line 2-2 of Fig. 1, Fig. 3 is a front elevation with the gong removed. and Fig. 4 is a central vertical section through the electromagnet.

In the drawings, the invention is illustrated as embodied in a single stroke electric bell. The base 1 of the electric bell is provided with screw receiving ears 2 by which it is mounted on a wall. The bell proper or gong 5 is mounted by means of a screw 6 on a bridge 7 which in turn is secured at its ends by screws 8 to the base 1. The lower part of the base 1 is round, conforming to the she e of the ong 5. The upper end of the use extcn 5 above the gong, and is provided with a cover plate 10 secured to the base by means of screws 11.

The gong is struck by a striker which comprises a hub 17, an arm 16 extending downwardly from the hub and a hammerhead on the free end of the arm. The hub 17 is rotatably mounted by means of its reduced ends 18 which are journaled in the base plate 1 and cover plate 10. The striker is actuated by means of an clectro-magnet 20 and. its armature 21 which is connected to the striker by means of a chain 22.

The electro-magnet 20 is mounted on the base plate 1 and has the usual U-shaped soft iron core, comprising the two pole pieces 25 and the yoke '26. Surrounding the pole pieces 25 are the usual magnet coils 27 which are connected by lead wires 28 with the binding posts '29 by means of which the bell is connected to the energizing circuit. The pole pieces 25 are provided with internal pin receiving bores 30. In the lower end of these bores are threaded the screws 81 which secure the yoke 20 to the pole pieces .25. The upper ends of the bores 30 are left open. Mounted on the upper faces of the pole pieces 25 are washers 32 of brass or other non-magnetic material for preventing the armature from sticking to the pole pieces after the electric circuit is broken.

The armature 21 is located immediately above the magnet 20 and consists of a soft iron bar. Projecting downward from the armature are two brass guide pins 10 which are loosely received in the bores 80 of the magnet pole pieces. Projecting up from the middle of the armature bar is an arm 11 which extends substantially parallel with the pins and terminates a little below the hub 17. The upper end of the arm 11 is substantially in line with the middle of the armature and the left-hand side of the hub 17.

The chain 22 is what is commonly known as a ladder chain, each link of which consists of a U-shaped piece of wire having its free ends bent over the transverse portion of the next link. The chain 22 passes up on the left-hand side of the hub 17, then over the top of the hub and down the opposite side. The end of the chain is secured by havin the striker arm 16 passed through the end link so as to engage the transverse portion of the end U-shaped link. The other end of the chain is secured to the free end of the arm 41 by means of a short piece of wire or pin 45 extending through a transverse hole in the arm 41 and having the free ends of the end U-shaped link bent about it. A stop )in 46 having a soft rubber sleeve is engaged by the striker arm 16 when it falls. Another pin 47 above the armature 21 prevents the accidental witl'idrawal of the guide pins 40 from the pin-receiving bores. The armature 21 is what may be termed a lioating armature since it is connected to the striker only by the flexible chain 22 and is guided solely by the guide pins 40 which loosely fit in the bores 30. The magnetic pull exerted on the armature is in a direction substantially parallel to the pole pieces :25. The guide pms +0 move in the pin-receiving bores in the direction of the magnetic pull, and there is, consequently, no side thrust on the pins due to the pull of the magnet on the armature. The arm 41 is substantially parallel with the guide pins -20. The chain 22 extends from the end of the arm 41 to the hub 17 in the same direction, that is, in the direction of movement of the armature. As the hub 17 is round, the direction of pull of the chain is unchanged as it is unwound from the hub as the armature is drawn down. The pull of the magnet on the armature may be considered to be centered at the middle of the armature which will consequently be the point of application of the force. The point of application of resistance is at the end of the arm -l1 at some distance from the point -of application of the force, and the line joining these two points extends in the direction of movement of the armature under the constraint of the guide pins *0. Consequently, this application of the force and the resistance to the armature will not only cause the armature to move in a straight line without side thrust, but will also prevent the armature from having a tendency to rotate or twist. The guide pins therefore slide freely in the bores 30 without bindin The chain 22 is long enough so that when the armature is arrested by contact with the ma net pole pieces and the hammer head 15 is in contact with the inside of the gon the chain is a little loose.

This ermits the hammer head to fall a little istance away from the gong after it has struck it, so as not to interfere with the vibration thereof. The pull of the armature 21 is sufiiciently strong so that, as the armature is drawn down, the hammer head 15 ac uires suiiicient momentum to strike the bel after the armature 21 is arrested by the magnet and the chain 22 loosens.

When the circuit connected to the binding post 29 is closed by a push button or other circuit closer, the magnet 20 is energized and attracts the armature which moves into the dotted line position shown in Fig. 3. The movement of the armature causes the chain 22 to turn the hub 17 and bring the hammer head 15 into contact with the gong 5 as indicated by dotted lines in Fig. 3. After the hammer head has struck the gong, it drops back a little on account of loosencss of the chain so as not to interfere with the vibration of the gong. After the circuit is opened, the magnet is decnergizcd, the striker falls into the full line position, shown in Fig. 3, because the hammer head 15 serves as a counterweight for the armature 21 and lifts the armature from the magnet.

While the striker mechanism of the present invention is illustrated in connection with the type of gong usually employed with electric hells mounted on the walls, nevertheless, other kinds of gongs or sound producing members may he used in place of the particular type of gong illustrated. A chain 22 is )referably employed as the flexible connecting line between the striker hub and the armature. but other forms of flexible lines might be used. Similarly, guiding means for the floating armature other than the guide pins and pin-receiving bores in the pole pieces may be employed. The present invention is, therefore, not limited to the illustrated embodiment but may be enibodied in other constructions of elec' tric bells within the scope of the invention as set forth in the following claims.

I claim- 1. An electric hell having, in combination, a gong, a striker comprising a rotatably mounted hub, an arm projecting from the hub and a hammer head on the arm, an electro-magnet below the hub, armature above the magnet, guides for the armature permitting it to rcciprocz to to and from the magnet, an arm extending upwardly from the middle of the armature in a direction substantially parallel with the movement of the armature, a flexible line extending from the end of the arm to the hub about which it is wound for operating the striker when the armature is attracted upon energizing the magnet, said line extending substantially in the direction of movement of the armature and serving by its resisting pull to hold the armature from rotation.

2. An electric bell having, in combination, a gong, a striker comprising a rotatably mounted hub, an arm projecting from the hub and a hammer head on the arm, an electro-magnet below the hub, an armature above the magnet, guides for the armature permitting it to reciprocate to and from the magnet, a flexible chain connected to the armature, wound over the top of the hub and having its end secured to the hub by means of the striker arm which is passed through a link of chain for operating the striker when the armature is attracted upon energizing the magnet, said hammer head scrvmg as a counterweight to lift the armature from the magnet after it is deenergized.

3. An electric bell having, in combination, a gong, a striker comprising a rotatably mounted hub, an arm projecting from the hub and a hammer head on the arm, an electro-magnet below the hub, an armature above the magnet, guides f or the armature permitting it to reciprocate to and from the magnet, a flexible line connected to the armature and wound over the top of the hub so as to operate the striker when the armature is attracted upon energizing the magnet, said hammer head serving as a counterwei ht to lift the armature from the magnet after it is denergized.

4. An electric bell having, in combination, a gong, a striker comprising a rotatably mounted hub, an arm projecting from the hub and a hammer head on the arm, an elec-' tro-magnet below the hub having upwardly facin pole pieces with pin-receiving bores extending downwardly therein, an armature above the magnet having downwardly extending guide pins loosely fitting in said pinreceiving bores, a flexible line connected with the armature and wound over the top of the hub so as to turn the hub and cause the ham mer head to strike the gong when the armature is attracted upon energizing the magnet, said hammer head serving as a counterweight to lift the armature from the magnet after it is denergized.

5. An electric bell having, in combination, a gong, a rotatably mounted striker comprising an arm an a hammer head on the free end of the arm, an electro-magnet, an armature above the magnet, guides loosely engaging the armature and permitting it to reciprocate to and from the magnet, a flexible line extending from the armature to the striker in the direction of movement of the armature for operating the striker when the armature is attracted u on energizing the magnet, said hammer ead serving as a counterweight to lift the armature from the magnet after it is deenergized.

6. An electric bell having, in combination. a gong, a rotatably mounted striker comprising an arm and a hammer head on the free end of the arm, an electro-magnet, an armature above the magnet, guides loosely engaging the armature and permitting it to reciprocate to and from the magnet, an arm ex- ,ending upwardly from the armature in a direction substantially parallel with the move ment of the armature, a flexible line extending from the end of the arm to the striker for operating the striker when the armature is attracted upon energizing the magnet, said line extending substantially in the direction of movement of the armature and serving by its resisting pull to hold the armature from rotation, and said hammer head serving as a counterweight to lift the armature from the magnet after it is deenergized.

7. An electric bell having, in combination, a gong, a striker comprising a rotatably mounted hub, an arm projecting downwardly from the hub and a hammer head on the arm, an electro-magnet below the hub having upwardly facing pole pieces with pin-receiving bores extending downwardly therein, an armature above the magnet having downwardly extending guide pins loosely fitting in the pin-receiving bores and having an arm extending upwardly from the middle of the armature in a direction substantially parallel with the guide pins and terminating substantially in a line with the middle of the armature and one side of the hub, a flexible chain extendin from the end of the spindle up said side of the hub, over the top of the hub and down the other side of the hub and having its end secured to the striker arm, said chain being loose when the armatuie is arrested by contact with the magnet pole piec s and the hammer head is in contact with the gang, the arma ure and chain serving to turn the hub and impart sufiicient momentum to the hammer head to strike the gong after the armature is arrested and the chain is loose.

FRANK S. TUCKER. Witnesses:

EMANUEL TUCKER, GEO. E. S'rennms.

7 Ooplu of this patent any be obtained tor an cent: each, by addressing the Commissioner of Patents,

Washinston, I). 6. 

